Tuesday, 18 December 2018

And a... godwit... in a pear tree?

When you think of Christmas the first bird that comes to mind is probably not the Bar-tailed Godwit. Yet there is one similarity between this bird and the jolly bearded man who delivers Christmas from the Arctic Circle - the journeys each undertakes.

The Bar-tailed Godwit subspecies, Limosa lapponica baueri, holds the record for the single longest non-stop migration of any avian species, clocking up between 10,000 and 11,000 km as it crosses the Pacific Ocean from its breeding grounds in Alaska to its wintering grounds on the shores of Australia and New Zealand. Closer to home, ‘our’ Bar -tailed Godwit subspecies, Limosa lapponica, admittedly has a slightly easier time of it, migrating from the Arctic Circle in Norway to overwinter on Irish shores from late August until March or April. That being said, I don’t think I’d fancy swapping my daily commute for their biannual trek.

Bar-tailed Godwit in winter plumage with satellite tracking device attached to its back.
John Fox.
Prior to undertaking such long migrations, these little birds must first ‘bulk up’. Their fat reserves increase phenomenally, finally comprising over half their body weight while their digestive organs shrink to accommodate this increase. As  Bill Bailey so aptly put it, this is a ‘form of self- cannibalisation’ (1), a gory feat which Santa Claus has thus far been able to forego.

The Dublin Bay Birds Project colour-ringing scheme, which began in 2013, has shed some light on the migration patterns of Limosa lapponica. With the aid of volunteers, one Bar-tailed Godwit, (DH), ringed on Sandymount Strand, has been recorded in Norway in the months of May and July over four consecutive years. This suggests that 'DH' is breeding in Norway, a finding supported by ‘An Atlas of Wader Populations in Africa and Western Eurasia’(2).

Bar-tailed Godwit ‘DH’ in breeding plumage – photo taken in Denmark.
Kim Fischer.
Colour-ring resightings have also revealed the potentially significant sites for these birds during their migration, with reports of Bar-tailed Godwits ringed by the Dublin Bay team submitted by volunteers in Denmark, the Netherlands and, most recently, England, prior to or following the breeding season.

Resighting locations of Bar-tailed Godwits outside Ireland.

Colour-ringing has also revealed some interesting patterns in terms of how Bar-tailed Godwits use Dublin Bay. Although all the Bar-tailed Godwits colour-ringed by the scheme so far were ringed on Dublin’s southside at Sandymount Strand, these marked individuals have been recorded using both the north and south sides of the bay. This is in contrast to the Oystercatcher which appears to be a bit more site-faithful. Many Oystercatchers ringed by the Dublin Bay Birds Project at either Sandymount Strand or Bull Island on Dublin’s northside, have only ever been resighted in Ireland at or near to these sites. For instance, two - hundred and fifty Oystercatchers ringed at Sandymount Strand have been resighted in Dublin Bay since 2013, with only 42 of these birds observed in the northern portion of the bay. Therefore, while Oystercatchers appear to largely conform to Dublin’s northsider/ southsider divide, Bar-tailed Godwits seem a more flexible bunch, availing of foraging and roosting opportunities on both sides of the bay.

Resighting locations of Bar-tailed Godwits in Dublin Bay. All Bar-tailed Godwits were ringed at Sandymount Strand on Dublin's southside.

Understanding the sites which are important to these incredible little birds on their migration to and from the Arctic and on our own shores outside the breeding period, enables greater national and international cooperation in protecting these sites. Colour-ring resightings feed into these conservation efforts and are a vital way to make a difference. Also, I have it on good authority that Bar-tailed Godwits act as spies for Santa Claus (courtesy of a five-year-old from Australia), so getting out and ring-reading may not only aid waterbird conservation but also pay off next Christmas!

Finally, from everyone in the Dublin Bay Birds Project, we wish you a Merry Christmas and Happy New Year. A massive thank you to everyone who has submitted ring resightings over the last number of years, your help really is invaluable!

(1) Bernhardt, A. (2016). ‘Interview: Bill Bailey on birdwatching, bar-tailed godwits and Brexit’ Country and Town House.
(2) Delaney, S., Scott, D., Dodman, T., & Stroud, D. 2009, An atlas of wader populations in Africa and Western Eurasia, 1st edn, Wetlands International, The Netherlands.

Friday, 9 November 2018

The Dublin Bay Birds Project - a quickfire digest of recent events (dive-bombing terns to evening gull watches)

We are continuing our quest to fill many of the gaps in knowledge about how birds use Dublin Bay. Being immersed in fieldwork and data the last while means we have not been blogging as often as we like to. It is now time to take stock, and look at what has been going on.  
The 2018 summer was equal parts challenging and exciting with a big focus on the breeding tern colonies in Dublin Port, while also doing the monthly low and rising tide counts of the whole bay.

But first let's take a moment to mention the DBBP video we made with Dublin Port Company and our friends in Media Coop. We had a lot of fun making it and the bird footage is STUNNING. In case you haven't already seen it, there is a little taster below as the full video can't upload here.  Full video available at this LINK.

Back to the terns. Oh the terns. No matter how many times we make the trips out to the Dublin Port tern colonies by boat, it never, ever gets old. The contrast of nature at its most dynamic and vital – 1000+ terns industriously incubating eggs and protecting nests and screeching in the air around the colonies - juxtaposed with the similarly industrious shipping vessels and port traffic going about their business all around them is an extraordinary sight. And we feel privileged to have the opportunity to be among the birds like this, up close and personal (sometimes very personal with direct hits to our heads from defensive adult terns). Plus, seeing the city from a boat in the Liffey Channel on a sunny day is pretty special.
Tara from the DBBP Team assisting with Common Tern data collection on the Great South Wall pontoon in July 2018. Helen Boland

In 2018, there were at least 596 pairs of terns, mainly Common but a few Arctic too, that nested on the four structures in the port area. The SPA-designated structure underwent significant upgrade works, carried out by ESB, and the terns seem to have adjusted to their excellent, new, specially designed platform. And the pontoon that was re-located pre-summer to a location close to the Great South Wall provided great views for walkers along the wall with a high volume of tern activity easily visible. You can read more about the summer tern monitoring in previous blog posts here and here

Post-breeding tern flocks at Sandymount
Once August arrived we began looking out for the huge annual congregations of post-breeding terns along Sandymount Strand. This is quite the event with thousands of terns gathering in the bay each night just before their southerly migration. As we’ve said here before, Dublin Bay has shown itself to be massively important over those few short weeks in August and September. The highest count we had this year was 6,700 ‘Commic’ Terns - Common and Arctic combined - in September (not quite the heady heights of 17,440 from September 2016 but impressive all the same!). And we had the pleasure of being joined by the South Dublin Branch of BirdWatch Ireland that evening to soak up the sheer spectacle of it. More about these awesome (in the proper sense of the word) tern gatherings here

The DBBP Team with the South Dublin Branch of BirdWatch Ireland looking at thousands of Terns in September on Sandymount Strand. Helen Boland.

In addition to the 135 tern chicks we colour-ringed at their nest sites we also managed to fit colour-rings to three fully-grown Common Terns that we caught in mist-nets in the dark after one of the flock counts in September. Hopefully these birds will be seen somewhere along their flyway helping us understand more about where they go. One of the Common Terns, ‘PFF’, that we colour-ringed in Autumn 2015 at Sandymount, has been seen three times since then in winter in the Gambia! Some previous observations of our colour-ringed terns are described here.

A Common Tern fitted with a Dublin Bay Birds Project, uniquely inscribed, colour-ring ‘2P3’ in September 2018. Helen Boland.

But now we're back in winter mode and the next task for the DBBP Team is a dusk gull roost count next week. It is incredible how many more gulls are present in the bay in the evening having been inland or at sea all day. We wouldn’t have a clue how important the bay is for gulls if we didn’t carry out specially tailored counts like this. Last year we counted more than 34,000 gulls one evening in December, mostly Black-headed Gulls (~29,000), with Herring, Common, Great Black-backed and Lesser Black-backed taking up the rear in that order.  Let’s see what we find next week. Then we move on to our third high-tide roost survey of 2018, with a dawn Brent census coming down the line too. And all the while we have been dealing with the steady influx of wader colour-ring resightings of our Dublin Bay Oystercatchers on their breeding grounds in Scotland and Iceland. More on all of that soon in another post.

We will share our news and findings more frequently now that we are back on top of our hectic schedule again! The information we are gathering improves our understanding of birds, how they use the bay, and what areas are particularly important for them, and hopefully it can help with informed decision-making about Dublin Bay.

Tuesday, 27 February 2018

Lights, Camera, Action

Last week we embarked on our first ever project video shoot. The aim was to produce a short video to describe the motivation behind the Dublin Bay Birds Project, the activities we undertake, and of course highlight the beauty of Dublin Bay whilst giving the wintering waterbirds the starring role.

Filming Bull Island south lagoon from a vantage point
close to the causeway
Ricky Whelan
It took the guts of five days to capture the bird footage, human bits, and narrative, and was a really great experience for the project team. We started filming during our recent Ring-reading Event at The Bull Island Visitor Centre and, with weather and tides on our side,  we got out to capture the bay at its best while searching for colour-ringed birds afterwards. 

Volunteers concentrate as they read colour-rings during
 the recent ring-reading event
Ricky Whelan
With almost five years of monitoring under our belt for the project, and with waterbird numbers at near peak levels, we knew where and when we would find the birds over the course of the few days. At Bull Island we captured the hustle and bustle of this waterbird hot-spot, not to mention a very obliging Golden Plover flock. It was also a great opportunity to film some of our colour-ringed birds up close! Filming also brought us to the Great South Wall to find small waders such as Turnstone and Sanderling, and plenty of gulls feeding on the rocks, tide edge, and river channel. We wanted to round it off in style and show the effect that the tide has on waterbird movements and activities. To do this we bedded-in for a full tidal cycle at Merrion Spit, an embryonic sand dune which is a roosting site for thousands of waders at high tide. We trudged the gear out at low tide, and with a short set-up window we got the gear in place and camera positions set. The time-lapse camera was ready, Francois and Theo, our cameramen, were in position, and by god did the birds and tide perform. 

Filming at a "secret location" Ricky Whelan

Francois busily filming the waders on the tide-line
 as a "V" of Brent Geese fly overhead
Ricky Whelan

Theo gets comfortable before a five-hour stakeout Ricky Whelan
Overall it was a massively enjoyable week and it gave us a small insight into the amount of effort, experience and knowledge it takes to film wildlife. We couldn't have asked for more in relation to the birds, the weather and the tides, and we now sit impatiently as we await the finished result. We will share the final product with you all very soon!

Time-lapse camera captures thousands of
 waders as they roost on the high-tide line
Ricky Whelan

Thanks to the great team at Media Coop, with particular thanks to Francois Gray for filming, producing and generally doing everything. Big thanks also to our awesome wildlife cameraman for the duration, Theo Jebb. We are grateful to Dublin Port Company for supporting the making of the video.

Tuesday, 16 January 2018

Adding Value to a Days Birdwatching

Back in October 2015 the Dublin Bay Birds Project Team hosted a 'ring-reading’ event at Bull Island Visitor Centre, see here. On Saturday, February 10th 2018, we are pleased to be running another similar one and we would love you to come along.

Colour-ringed Redshank John Fox

The event acts as a way for us to thank and provide feedback to  the observers who have been submitting their observations of colour-ringed wintering waders to us, but, also, we would love to help more people get involved with this element of the Dublin Bay Birds Project. The Citizen Science contribution to the project is of immense value and crucial to this work.  We would like to encourage even more new Citizen Science contributors and catch up with established project contributors.

Ring-reading Event Poster BirdWatch Ireland

Since 2013,  we have ringed more than 1700 waders in Dublin Bay of which over 500 are colour-ringed (376 Oystercatchers, 99 Bar-tailed Godwits, and 41 Redshank). But all of that means nothing if nobody tells us where they spot them and the context of their observations. With five years of colour-ring resighting information now compiled we are seeing some interesting stories beginning to emerge. 

DBBP Ringed Oystercatcher Resightings From Scotland BirdWatch Ireland

All of the observations we receive paint a picture of where the birds go to breed and what routes they take to get there, and they play a key role in identifying staging sites. But, importantly, your observations of colour-ringed birds in Dublin Bay provide valuable information about how they use the bay for feeding & roosting. This information in turn informs our policy work and our conservation efforts, and it opens up dialogue with our colleagues internationally to feed into international bird studies and conservation management. 

Sample Resighting Report/Bird History BirdWatch Ireland

What we want you to do is - stop when a colour-ringed bird catches your eye and, if possible, read and note the ring inscriptions. With that done you can enter your observation online and we will get back to you with the movement histories for that bird. All sounds simple, but of course it takes a bit of practice, concentration, and a good pair of binoculars or a telescope! If you would like to find out more or just want to come hear about the project and meet like-minded people we would love to see you on February 10th at 10am at the Bull Island Visitor Centre.